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प्रश्न
The electricity bill specifies the usage in _______.
पर्याय
kilowatt
joule
volt
unit
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उत्तर
The electricity bill specifies the usage in unit.
APPEARS IN
संबंधित प्रश्न
An electric heater of resistance 8 Ω draws 15 A from the service mains 2 hours. Calculate the rate at which heat is developed in the heater.
Why is the tungsten used almost exclusively for filament of electric lamps?
What is nichrome? State its one use.
Give two reasons why nichrome alloy is used for making the heating elements of electrical appliances.
Why is a series arrangement not used for connecting domestic electrical appliances in a circuit?
A resistance of 25 Ω is connected to a 12 V battery. Calculate the heat energy in joules generated per minute.
How much heat will an instrument of 12 W produce in one minute if it is connected to the heat produced by it?
The current passing through a room heater has been halved. What will happen to the heat produced by it?
Name the material which is used for making the filaments of an electric bulb.
The current passing through an electric kettle has been doubled. The heat produced will become:
(a) half
(b) double
(c) four time
(d) one-fourth
The elements of electrical heating devices are usually made of:
(a) tungsten
(b) bronze
(c) nichrome
(d) argon
Two exactly similar heating resistances are connected (i) in series, and (ii) in parallel, in two different circuits, one by one. If the same current is passed through both the combinations, is more heat obtained per minute when they are connected in series or when they are connected in parallel? Give reason for your answer.
Give Scientific reason.
In practice, the unit kWh is used for the measurement of electrical energy, rather than joule.
Statement 1 : Electric current ( flow of electrons ) creates heat in the resistor.
Statement 2 : Heat in the resistor is created according to the rule of energy conservation.
Explain Statement 1 with the help of Statement 2.
Name any six domestic appliances based on the heating effect of electric current.
In an electric bulb, coil of _______ metal is used.
Which of the following substance contracts on heating?
What is the heating effect of electric current?
What is used to turn off the sudden increase in current in the electrical circuit of the house nowadays?
Explain the application of heating effect of electric current in an electric bulb with a diagram.
Define fuse.
Name some devices that run using heat effect of electric current
A fuse wire repeatedly gets burnt when used with a good heater. It is advised to use a fuse wire of:
A current of 1 A is drawn by a filament of an electric bulb. Number of electrons passing through a cross-section of the filament in 16 seconds would be roughly:
An electric kettle consumes 1 kW of electric power when operated at 220 V. A fuse wire of what rating must be used for it?
B1, B2 and B3 are three identical bulbs connected as shown in Figure. When all the three bulbs glow, a current of 3A is recorded by the ammeter A.
- What happens to the glow of the other two bulbs when the bulb B1 gets fused?
- What happens to the reading of A1, A2, A3 and A when the bulb B2 gets fused?
- How much power is dissipated in the circuit when all the three bulbs glow together?
Paheli took a wire of length 10 cm. Boojho took a wire of 5 cm of the same material and thickness. Both of them connected the wires as shown in the circuit given in the following figure. The current flowing in both the circuits is the same.
- Will the heat produced in both cases be equal? Explain.
- Will the heat produced be the same if the wires taken by them are of equal lengths but of different thickness? Explain.
What are the uses of electromagnets?
Explain the working of an electric fuse.
It would cost a man Rs. 3.50 to buy 1.0 kW h of electrical energy from the Main Electricity Board. His generator has a maximum power of 2.0 kW. The generator produces energy at this maximum power for 3 hours. Calculate how much it would cost to buy the same amount of energy from the Main Electricity Board.
Copper wire offers very little ______ and does not get heated up quickly.
Fuse is a strip of alloy wire which is made up of lead and tin with a very low ______.
Match the following
| 1. | Bulb | a. | Conductor |
| 2. | Electroplating | b. |
Insulator |
| 3. | Pure water | c. | Heating effect of current |
| 4. | Salt solution | d. | Chemical effect of current |
Name the effect of the current responsible for the glow of the bulb in an electrical circuit.
An electric fuse is a wire made up of a material having ______ melting point.
A trip switch is a ______ safety device.
If 220 V potential difference is applied across an electric bulb, a current of 0.45 A flows in the bulb. What must be the power of the bulb?
Two students decided to investigate the effect of water and air on iron object under identical experimental conditions. They measured the mass of each object before placing it partially immersed in 10 ml of water. After a few days, the object were removed, dried and their masses were measured. The table shows their results.
| Student | Object | Mass of Object before Rusting in g |
Mass of the coated object in g |
| A | Nail | 3.0 | 3.15 |
| B | Thin plate | 6.0 | 6.33 |
What might be the reason for the varied observations of the two students?
The graph of voltage vs current for four different materials is shown below.
Which of these four materials would be used for making filament of bulb?
